Detection of radar signal in noise using optimum time-frequency receiver

An optimal time-frequency receiver based on wavelet transforms is presented in this paper. To characterize the transient in time-varying radar signals, a more generalized representation which can reflect both the time and the frequency behavior of signals is desirable. The joint time-frequency representation provides a way to localize information in both the time and the frequency domain, simultaneously. We use wavelets sampled in both the time and the frequency domain as an orthonormal basis to represent radar signals in the joint time- frequency domain. With the wavelet representation, the optimum time-frequency receiver can be derived. The joint time-frequency representation allows us to separate signals and interferences which may not be separatable by conventional time gating or frequency filtering. In this paper, we also describe some general issues on the detection of known signals, the detection of signals with unknown parameters and the wavelet based estimation of parameters.